The invention relates to an apparatus and method for the selective, locally defined heating of an object. The invention is particularly applicable to the destruction of malignant cells or tumors in a human body by the local heating of the cells or tumors. Heretofore, it has not been possible to effect destruction of malignant tumors or the like by local heating thereof without having to operate, cutting open the body.
The apparatus according to the present invention is capable of destroying malignant cells or tumors located within a body by selective, locally defined heating, while the tissues surrounding the malignant cells or tumors are not destroyed. The apparatus and method according to the present invention can be used in conjunction with other treatments, such as medications which prevents cell division, or ionizing radiation.
High frequency radiation, is eminently suited for the practice of the present invention since, it acts in the preferred manner within the depth of the body, and does not cause burns on the surface of the skin, and complex heating fields can be built-up within the body by using a plurality of transmitters focused at the same general volume. Additionally, according to the present invention, the desirable irradiation is accomplished with a minimum expenditure of energy, and low transmitting power. The transmitters simultaneously irradiate energy on a defined volume so that there is an energy concentration at the defined volume which is well beyond the transmitting power of each of the individual transmitters, resulting in destruction of the malignant cells or tumors (which have a lower tolerance to such radiation than healthy cells) while not harming the surrounding normal tissue.
To accomplish the desired effects, according to the present invention a plurality of high frequency heat radiation-emitting transmitters are mounted to an inner surface of a ring in such a way that radiation beams emitted by the transmitters intersect each other generally within a common volume, which common volume is generally encompassed by the ring. Preferably the transmitters are microwave antennas, solid-state antennas being preferred since they have a low continuous power output but a high pulse power output. Such antennas which are capable of emitting a few milliwatts of microwave energy in continuous operation are capable of emitting approximately ten times higher power levels of radiation in pulse operation, and the combined effect of the plurality of transmitters can result in a considerable energy concentration within the volume at which they are focused. According to the present invention microwave pulses of up to a few kilowatts can act on locally narrowly defined body areas and reliably destroy malignant cells.
In order to facilitate focusing of the transmitters on virtually any body part, particular mounting means for the transmitters and ring, and particular focusing means may be provided. For instance, mounting means may be provided which allow linear reciprocation of the ring along a dimension generally perpendicular to a plane containing the ring, allow rotation of the ring about its center, and allow pivoting of the ring about either of two perpendicular axes disposed in the plane of the ring. Further, the transmitters may be mounted so that they are radially movable with respect to the ring, and slightly pivotal with respect to the ring. To facilitate focusing of the beams, radially-extending electromagnetic coils may be provided surrounding the transmitters. Proper positioning and focusing of the transmitters may be effected in response to signals generated by ultrasonic generators positioned adjacent the transmitters.
In order to enhance the effect of the radiation upon the body, a plurality of magnets may be mounted to the ring to effect a polarization and enhance conductivity of the human body and irradiate it. All operations may be suitably monitored electronically, and suitably controlled, as by utilizing conventional available computer technology.
In practicing the method according to the present invention, a human body is placed so that it is partially disposed within the ring (preferably the body extends horizontally, being supported by an apertured table). The movement of the ring and/or transmitters is effected so as to focus radiation in the areas of the body where malignant body cells or tumors are located, and energy is supplied to the transmitters. The energy may be pulsed, and may be supplied to the transmitters in sequence. The transmitters preferably are constructed and the transmitter movement and energy supplication steps are practiced, so that the diameter of each radiation beam from each transmitter is about 1-30 cm (preferably 2-10 cm.) at the center of the ring.
It is the primary object of the present invention to provide a method and apparatus for the efficient selective, locally defined heating of an object, particularly a human body having malignant cells. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.